Adjustable multiple section lifting robs



Mar h 10 1964 D. B. CHESKIN .ADJUSTABLE MULTIPLE szcnou LIFTING RODS Filed Oct. 22, 1962 Figu e 2 INVEN TOR.- DGV/d chaskin A TTOR Y United States Patent M 3,12d,tl14 ADJUSTABLE MULTIELE SECTEQN LE TING RD David Cheshin, 497 S. Dearhorn, Chicago 5, ill. Filed 6st. 22, 1962, Ser. No. 232,647 4 Qlaims. (Cl. M -575) The present invention relates to an improved demountable multiple piece notch-form of lifting rod suitable for use with jack-means for lifting heavy loads. For example, as described in my Patent No. 3,028,144 covering Lifting Apparatus, one or more pairs of notched lifting rods or bars are used with jack-means and suitable hinged or lifting members or pawl means which are in turn adapted to engage the notch-like portions of the rods such that the latter may be raised through incremental stages with an attached load. A notched-form of lifting bar may be cut from a flat or rectangularly shaped bar section, however, such cutting by a steel saw or cuttmg flame is time consuming and expensive. Particularly, when a large number of the notched-form of bars are required, the cost of labor to cut and smooth the surfaces of such tapering shoulder sections on a large bar or rod would be prohibitive.

It is, therefore, a principal object of the present invention to eliminate expensive fabrication and cutting operations by providing a multiple section construction which embodies the placing and/ or stringing of a plurality of tapering preformed sections onto a tension core rod to form the desired sloping sides and shoulder sections thereon.

It is another object of the invention to construct a notched-form of bar or rod from a plurality of tapered cast iron or cast alloy metal sections which are adapted to be rapidly slid over or engaged with a standard form of long tension rod.

A still further object of the invention is to provide a notch-form of lifting bar or rod which may be prestressed to in turn permit greater loading conditions.

Many advantages are attained by the use of cast or preformed sections, other than the initial elimination of slow cutting and grinding operations. For example, worn portions of the improved form of multiple section rod may be readily repaired by replacing the one or more particular portions of the string of cast sections without discarding and replacing an entire bar unit. By using cast sections to form the exterior wearing and bearing surfaces, it is possible to obtain a surface hardening treatment on each piece which will in a preferable embodiment result in a rod far superior to that obtainable from a cut surface or bar stock. Still another advantage of the present improved design and construction is that cast pieces can be formed to have shoulder or indentation means which provide that adjacent sections will readily engage one another in a non-turning manner.

In one embodiment, the present invention provides an adjustable multiple section, notch-like, lifting rod comprising in combination, a continuous core rod, a plurality of tapered holding sections positioned in an engaging sequence over said core rod, each of the sections having axial openings sized to pass over said rod and further having shoulder means at least at one end thereof to engage the next adjacent section whereby to preclude rotation of said sections, with respect to one another, and holding means at each end of said central rod to retain said sections in engagement thereon.

The tapered sections may be formed from normal cast iron, or alternatively various types of cast steel or alloy, such that any type of surface may be obtained to give a good wearing surface. In other words, it is not intended to limit the present invention to any one type of steel or surface treatment. Actually, cold-rolled forms of steel arrears Patented Mar. 10, 1964 bars may be further rolled or forged to form tapered sections, however, it is desirable to eliminate expensive fabrication steps in the formation of the tapered sections and the use of a single form or mold will generally suffice to cast a multiplicity of tapered sections which may be rapidly assembled into the desired multiple section lifting rod. Individual cast pieces are preferably subjected to a surface hardening treatment to insure a long life to the wearing surface and permit each of them to withstand high compression forces from the lifting edges of the lifting apparatus or pawl means which are in contact during a lifting operation.

There is still another advantage in the present design and construction utilizing separate removable tapered sections and a separate high tensile strength core-member, particularly from the fact that the core rods may be supplied from standard high tensile strength steel stock. For example, high tensile strength rods may permit working stresses of the order of 80,000 pounds per square inch, or higher. The core rods may, of course, be supplied in varying lengths to accommodate a particular lifting operation.

The design and construction of the present improved multiple section lifting rod, as well as additional advantageous features in connection therewith, may be better set forth and understood by reference to the accompanying drawing and the following description thereof.

FIGURE 1 of the drawing is an elevational view, partially in section, of an assembled multiple piece lifting rod, showing cast sections which are of a tapered rectangular form.

FIGURE 2 of the drawing indicates a plan view of a rectangular form of tapered section, such as utilized in FIGURE 1.

FIGURE 3 of the drawing is a sectional elevational view of a special tapered splicing section which is utilizable to join two sections of core rods.

FIGURES 4 and 5 of the drawing indicate diagrammatically, in plan view, two additional forms of tapered section.

FIGURE 6 indicates a tapered rectangular form of section adapted to fit over a square or rectangular form of center core bar.

Referring now to FEGURES 1 and 2 of the drawing, there is shown a plurality of tapered sections 1 which are of a trapezoidal shape and adapted to slide over a core rod 2. In the present embodiment, the core rod is indicated as being threaded at each end and having washers 3 and threaded nuts 4 which serve to hold in place the plurality of sections 1.

In order that each tapered section will maintain in proper position in the same plane with the remaining sections, there is provided a recessed or notched portion 5 within the wide, lower portion, as indicated in FIGURE 1. The recessed or notched portion is sized to slidably fit over the upper end portion of the next lower tapered section. Thus, as long as there is sufiicient width to the tapered section, the engagement of the upper portion of a section with the recessed part 5 of the next higher section will preclude one section turning with respect to the other. Various types of shoulder arrangements or prongs may be, of course, provided to preclude adjacent sections from turning with respect to one another so that the entire string of sections in the multiple piece lifting rod will be maintained in a desired plane. On the other hand, where truncated cone sections are utilized to form the multiplicity of tapering sections on the rod, then the provision for having an engagement between one section and the next is of lesser importance since a slight turning of any one section will not interfere with the assembled lifting rod in its operations with lifting apparatus operating to effect incremental lifting of a load at the end of the rod. in the casting of a tapered section 1, teams may be provided for having axial openings longitudinally through each of the sections. For example, the present embodiment indicates end openings 6 adapted to slidably fit over the rod 2 and a larger hollow internal area 7 which will serve to lighten the weight of each section and at the same time provide passage for the longitudinal core rod 2. At the present time, cast openings of a predetermined size can be made quite accurately, however, where desirable there may be a quick grinding or boring operation utilized in connection with each piece to insure the sizing of the opening to provide a slidable fit over a predetermined sized center tensile rod.

As noted hereinbefore, an additional advantage of the present design resides in the use of a separate core rod such that the rod members in an assembly may be prestressed to permit greater loadings on the assembled rod for lifting operations. The thread and nut arrangement permits adjustability and the take-up of slack at any given time in a prestressing stop, as well as to insure that all of the multiplicity of tapered section in a unit are maintained in contact with one another.

In Fl-GURE 3 of the drawing, there is indicated a tapered section in which may, for example, have an outside configuration similar to the tapered section 1 of FXGURE 1, such that it may be used with a plurality of sections on any given core rod. However, the special section 10 is cast to have a small axial opening which may be subsequently threaded to accommodate threaded ends 5 of core rod 2 and in turn serve as an elfective splice section for the lengthening of a core rod. Section 1a has a lower recessed or notched area 5', as do the other tapered sections to be used therewith, so that the upper end of a next lower section will engage therewith and prevent the turning of the string of sections.

in FIGURE 4, there is indicated, in plan view, a modified form of tapered section 9, which has a generally oval shaped horizontal cross section. In a longitudinal cross section, the tapered section 9 will have a trapezoidal form, similar to the sections 1 in FEGURE 1 of the drawing, so that the tapered walled surface thereof will accommodate a hinged or pawl-like lifting member. The lifting members of a given lifting apparatus being adapted to slide along the tapering surfaces and engage beneath each section of the string of sections. The oval-form tapered section of FIGURE 4 is likewise provided with a central opening 18 so that it may provide a sliding fit over a core rod. Also, the lower wide portion of the section 9 is provided with a suitable recessed or notched portion which is sized to fit over and engage with the smaller top end of the next lower section to preclude turning of one section with another.

In FIGURE 5 of the drawing there is shown, in plan view, a truncated cone section 11, which in accordance with the present invention provides a tapering wall section adapted for stringing on a central core rod. End axial openings 13 being sized in the casting or other fabrication of the section 11 to fit over an axial core rod and provide a multiple section rod assembly. The embodiment of FIGURE 5 shows projecting ribs or luglike projections 12 which may be sized to engage with suitably sized slots or recesses formed in the lower ends of each unit. In other words, although not shown on the drawing, the lower enlarged section of each member will have shallow recessed portions adapted to accommodate the engagement of the upper circular end portions of the next lower unit as well as extended slots which will accommodate the lug-like projection 12 on the top of each unit. There is, thus, provided a slot and key arrangement which will preclude one section from turning with respect to another.

Referring now to FIGURE 6 of the drawing, there is shown a tapering section 111 which may be similar to the tapered sections of FlGURES l and 2 except that a square or rectangular center opening 14 is adapted to slidably fit over a square or rectangular core rod. use of a shaped center rod of high tensile strength steel will preclude the use of notches and the like to preclude the twisting of one section with respect to another and thus simplify the design of the separate sections. In addition, it may be thus pointed out that the central core member may be of cross section other than round, although round cross section rods or cable is generally more readily available than other forms of high tensile strength bars.

it is to be understood that numerous shapes may be utilized to form the longitudinal tipering sections which may be strung on a central core rod to form an adjustable multiple section lifting rod. it is, however, within the scope of the present invention to provide means for the engagement of one section with an adjacent section to preclude turning and one or more various types of notch and key arrangements may be utilized in the casting or forming of an individual tapering section. The present drawing has indicated the assembling of the tapering sections such that all of the small ends are at the top and the tapering of the wall portions are from a smal top to a large bottom portion, however, lifting rods may, on occasion, be used in a reverse position with enlarged end portions at the top when mounting the rod for use with a lifting apparatus. In other words, the plurality of tapered sections from a toothed rod which may be ellectively climbed in incremental stages by a lifting apparatus.

I claim as my invention:

1. An adjustable multiple section notch-like lifting rod comprising in combination, a continuous rigid core member, a plurality of tapered holding sections positioned in an abutting and engaging sequence over said core member, each of said sections shaped and positioned to have lower pro'ccting portions symmetrical with respect to said core member and having central openings sized to pass over said core member and further having keying means at least at one end to engage the next adjacent section and precluding rotation of said sections with respect to one another, and holding means at each end of said core member to keep said sections in abutting engagement thereon.

2. The multiple section lifting rod of claim 1 further characterized in that said core member is formed of hi tension strength steel and each of said tapered holding sections are formed of surface-hardened cast metal.

3. The multiple section lifting rod of claim 1 further characterized in that said tapered holding sections are of a substantially rectangular cross section and the larger end portion of each section is provided with a rectangularly formed recessed notch of the size of the smaller end thereof and thereby provide a sliding fit with respect to the next adjacent section.

4. The multiple section lifting rod of claim 1 further characterized in that each of said tapered holding sections have a circular-form cross section, the smaller end portion of the tapered section has at least one protruding lug from a side thereof and the opposing larger end portion thereof is provided with a recessed notch of the size of said protruding lug to provide a sliding fit over the protruding lug of the next adjacent section.

References Cited in the file of this patent UNITED STATES PATENTS Smith Oct. 7, 1873 McArdle et a1. June 5, 1934 The 

1. AN ADJUSTABLE MULTIPLE SECTION NOTCH-LIKE LIFTING ROD COMPRISING IN COMBINATION, A CONTINUOUS RIGID CORE MEMBER, A PLURALITY OF TAPERED HOLDING SECTIONS POSITIONED IN AN ABUTTING AND ENGAGING SEQUENCE OVER SAID CORE MEMBER, EACH OF SAID SECTIONS SHAPED AND POSITIONED TO HAVE LOWER PROJECTING PORTIONS SYMMETRICAL WITH RESPECT TO SAID CORE MEMBER AND HAVING CENTRAL OPENINGS SIZED TO PASS OVER SAID CORE MEMBER AND FURTHER HAVING KEYING MEANS AT LEAST AT ONE END TO ENGAGE THE NEXT ADJACENT SECTION AND PRECLUDING ROTATION OF SAID SECTIONS WITH RESPECT TO ONE ANOTHER, AND HOLDING MEANS AT EACH OF SAID CORE 